Thermostat.



PATENTED MAR. 7, 1905.

J. E. SHEPHERD.

THERMOSTAT.

APPLIOATION FILED APR. 25, 1904.

Jlami ep/ne'rd UNITED STATES Patented Maren '7, 1905.

JOHN E. SHEPHERD, OF CHICAGO, ILLINOIS.

THERMOSTAT.

SPECIFICATION forming part of Letters Patent No. 784,186, dated March 7,1905.

Application filed April 25, 1904. Serial No. 204,778.

To (l/ZZ whom it may concern.-

Be it known that I, JOHN E. SHEPHERD, of Chicago, in thelcounty of Cookand State of Illinois, have invented certain new and useful Improvementsin Thermostats; and I hereby declare that the following is a full,clear, and exact description thereof, reference being had to theaccompanying drawings, which form part of this specification.

My invention relates to improvements in thermostats adapted for use inconjunction with electric signaling systems, such as firealarm systemsand the like; and it has for its primary object to providea device ofthe character described which is simple in construction and efficient inoperation.

Other and further objects will become apparent from the followingdescription, taken in conjunction with the drawings, wherein Figure 1 isa horizontal section of a thermostat, taken on line 1 1 of Fig. 2. Fig.2 is a vertical section on line 2 2 of Fig. 1. Fig. 3 is adetail of oneform of circuit-controlling mechanism, and Fig. i is a detail of aslightlymodilied form of circuit-controlling mechanism.

Throughout the drawings like numerals of reference refer always to likeparts.

In the drawings, 5 indicates an insulatingcasing, preferably comprisinga substantially oblong body part having a Hat bottom 6, in the center ofwhich is formed a depression or well 7.

8 is a central perforation in the bottom of the well-wall.

9 and 10 indicate opposing metallic strips or springs arranged end toend in longitudinally-separated relation and suitably secured upon theflat bottom 6 of the thermostat-casing, so that their line of separationis over the well 7. 9 and 10 indicate similar metallic strips arrangedin parallelism to the strips 9 and 10 in like relation. The strips 9 and10 are adapted to be included in one circuit of a system and the strips9 and 10 in another circuit of the system. Associated with these partsis a circuit-controlling means of the thermostat, comprising movableparts adapted to normally close the circuits through the strips9 and 10and 9 and 10, and when moved in operation to first break the circuitcontinuity through said strips and subsequently to reestablish the sameand also establish an electrical cross connection between the circuitscomprising said strips. In the construction shown 11 is avertically-disposed rod having attached thereto two cross-bars,generally indicated by the numerals 12 and 13. These cross-bars are 11referably of wedge shape in cross-section arranged with their apexes inconfronting relation and disposed in the easing so that the cross-bar 12lies beneath the circuit-strips and the cross-bar l3 lies thereabove,both in vertical alinement with the separating-space between the stripsof the respective pairs. The cross-bar I2 comprises a central portion142., of insulating material, secured to the rod and having aflixed toits ends metallic conducting-pieces I5 and 15, adapted to make contact,respectively, with the strips 9 10 and 9 10. The cross-piece l3 metallicmember uninterrupted by insulation; but it may be, as illustrated at 13in Fig. I, composed of a central insulation-section 16 and metallicpieces 17 I7, separated by said insulation-section. Normally thecross-bar 12 of the circuit-controlling member is forced between thecircuit-strips 9 10 and 9' 10, so that its conducting portions 15 15complete the circuit through the said pairs of strips. The parts areheld in such position by a body 18 of fusible material, such as solder,joining the vertical 'rod II and the casing member. Preferably said bodyof material is on the outside of the casing at the bottom of the well,as indicated in Fig. 2. The arrangement of the device is such that thestem ll constantly tends to move in such direction as to bring the uppercross-bar 1?) into contact with the circuit-strips, in the presentembodiment such tendency being due to the action of gravity.

19 is a weight rigidly aflixed to the stem 11 and arranged within thewell 7, near the upper part thereof, to insure movement of the stem whenthe material 18 is fused. It will be api parent, however, that a springmight be subin the form shown in Fig. 3 is a continuous stituted for theweight 19, if desired, so that the device would move independently ofgravl ity, or that the two might be used conjointly.

In operation the parts are set in a position as indicated until the heatconditions become such as to fuse the body of solder 18 and release therod 11 from its restraint against downward movement. At such time underthe action of the weight 19 the rod 11 descends, carrying with it thecross-bars, so that the metallic portions 15 15' of the cross-bar 12leave contact with the circuit-strips and break both circuits throughthe thermostat. Immediately thereafter the upper bars 13 and 13 comeinto contact with the circuit-strips to complete the circuits throughboth wires leading into the thermostat. In the event the form ofcircuit-controlling means shown in Fig. I is used, however, thethermostat-circuits are first broken through both wires andreestablished, while if the form illustrated in Fig. 3 be employed thereestablishment of the circuits following the double break isaccomplished by the establishment of a cross connection between the twothermostat-wires.

While I have illustrated and described in detail an operative embodimentof my invention, it will be apparent that slight changes might be madetherein without departing from the spirit and scope of my invention.

Having described my invention, what I claim, and desire to secure byLetters Patent of the United States, is-

1. In a thermostat, separated parts adapted to be included in twoelectric circuits, a cir cuit-controlling means associated therewith,comprising a movable member, means associated therewith forindependently completing circuits through the circuit parts when themovable member is in normal position, and to break both circuits whenthe movable member is moved, means arranged to close the circuitsubsequent to the breaking thereof by the first-named means when themovable member is moved, and fusible means for normally holding themovable member against movement.

2. In a thermostat, separated parts adapted to be included in twocircuits, circuit-controlling instrumentalities comprising movable meansarranged when in normal position to close the circuits through saidcircuit parts and movable to break the circuits therethrough, othermeans normally disconnected from said circuit parts movable toreestablish circuit through said parts, after the rupture of the circuitby the first-named movable means, and means for normally holding saidcircuitcontrolling instrumentalities against movement.

3. In a-thermostat, separated parts adapted to be included in twoelectric circuits, a circuit-controlling structure comprising means fornormally closing the circuits through said circuit parts, other meansadapted to close said circuit parts normally disconnected from the same,and a means for moving said circuiteontrolling structure to break theconnection of the first said means with the circuit parts andsubsequently make connection of the secend said means with the circuitparts, and means for normally holding said structure against movement.

I. In a thermostat, the combination with circuit parts of means normallyclosing circuits through such circuit parts arranged for movement tobreak connection between the same, means normally out of connection withsaid circuit parts movable to reestablish circuit connections betweenthe same subsequently to the operation of the [irst said means, and abody of fusible material for holding said circuit-controlling partsnormally against movement.

5. In a thermostat, a casing, circuit-strips arranged within the casingin a plurality of parallel pairs, adapted to constitute parts of aplurality of circuits, the strips of each pair being separated, astructure comprising two vertically-separated cross-bars one normallyarranged to establish connection independently between said pairs ofstrips, and adapted when the structure is moved downward to breakconnection between said strips, and the other normally out of contactwith said strip arranged when the structure is moved downward to breakconnection between said strips, and the other normally out of contactwith said strips arranged when the structure is moved downward to makeelectrical contact therewith, and heat-releasable means for holding saidstructure against movement.

6. In a thermostat, a plurality of pairs of separated circuit-stripseach pair adapted to constitute part of an electric circuit, acircuitcontrolling structure con'iprising two circuitclosing bars oneprovided with conducting portions insulated from each other normallyarranged to close the independent circuits through said pairs of strips,and the other bar providing electrically-connected portions normallydisconnected from the circuit-strips, said structure being movable tolirst disconnect the first said bar from the circuit-strips, andsubsequently connect the second-mentioned bar with said strips, andheat-releasable means for normally holding the circuitcontrollingstructure against movement.

7. In a thermostat,separated parts adapted to be included in an electriccircuit, circuit-closing means normally making connection between saidcircuit parts and movable to break connection therebetween, anothercircuit-closing means normally out of connection with said circuit partsmovable to make connection therebetween subsequently to the breaking ofthe connection by the first said means, and means for normally holdingsaid I0 heat-releasable means for restraining said structure againstmovement with the firstacting of said conduetingpieces in circuitclosingposition.

In testimony that I claim the foregoing as my own I aifix mysignature inpresence of two 5 witnesses.

JOHN E. SHEPHERD. \Vitnesses:

GEORGE T. MAY, Jr., MARY F. ALLEN.

